The projects in this grant are directed to the understanding of basic biological phenomena that are important to the normal and abnormal function of cardiovascular, pulmonary, and renal systems and, in selected instances, clinical investigations that relate directly to these phenomena. Included are 24 individual projects organized under the categories of: Circulation, Cardiac Function, Muscle Biology, Neural and Chemical Regulation of the Cardiovascular and Respiratory Systems, Electrolyte Transport, Liquid Metabolism and Molecular and Cell Biology. Several Core Facilities support the program and the Responsible Investigators, all members of the staff of the Cardiovascular Research Institute, participate in a regular series of conferences designed to prom te communication and collaborative endeavors among the projects.